In this paper the lowest exciton levels of solid ${\mathrm{C}}_{60}$ are calculated. Based on the energy band structure of solid ${\mathrm{C}}_{60}$, a formula appropriate for calculating the spectra of optically produced excitons is given. An estimation of the lowest optically produced exciton levels in solid ${\mathrm{C}}_{60}$ is obtained which is consistent with various low-energy features observed in solid ${\mathrm{C}}_{60}$. We point out that the low-energy features in solid ${\mathrm{C}}_{60}$ should be attributed to excitonic effects and our calculation will benefit further understanding of excitonic effects in solid ${\mathrm{C}}_{60}$. © 1996 The American Physical Society.

• Received 19 January 1996

DOI:https://doi.org/10.1103/PhysRevB.54.4504